Andy Murray again frayed the nerves of a nation before beating Jo-Wilfried Tsonga in four pulsating sets on Centre Court. The Scot seems incapable of ordinariness. But, when he walks on to the sainted turf again on Sunday alongside Roger Federer, the tension will be ramped up to unprecedented levels for the first British men's finalist at Wimbledon in 74 years.

Those are weird words to write. They will be heavy sentiments for the player himself to digest because, whatever he says about trying to be selfish, about staying calm but focused, he does care what it means to the country, the game and all those who wish him well. And he would be made of stone if Saturday night were not a tough one to grab some sleep.

It would be nice if he played better than did the last home representative to get this far, Henry "Bunny" Austin, who took only four games off the great Don Budge in 1938. It would be nicer still if the Scot played more like the elegant, determined Fred Perry who, as we all know, was the last British champion here, winning the third of his titles in 1936 with similarly embarrassing ease against Gottfried von Cramm.

That is all history. Murray wants to make his own and on Friday he worked tirelessly if sometimes inattentively to get there, winning 6-3, 6-4, 3-6, 7-5.

The match was packed with incident. Murray slammed a hard shot directly at Tsonga in the last game of the third set, sending him to the grass clutching his groin – evidence of Ivan Lendl's hard-nosed input – and flirted more than once with disaster.

The match was a long way from fault-free but it was never dull. For that we have Tsonga to thank, too. He played in bursts of brilliance and distraction, the uncertainty adding to the entertainment.

"Andy is one of the people I don't like to play because he is returning really well," he said beforehand. "He can also play some really good passing shots and he's really quick." Talk about writing your own obituary. He would get several shots at a redraft.

The most exhausting drama was saved for the last shot of the match. Having looked as if he might blow a two-set lead, Murray rebounded steadily against the fading Frenchman in the fourth. After 11 games Tsonga was serving to stay in the match. He smashed at the net, where he had lived for an extraordinary 75 points during the match, then netted when he went there again in the next exchange. Murray, in a twinkling, had match point. He could not, in his wildest nightmare, have imagined the rattling forehand which left Tsonga stranded would be called out, though. The challenge favoured the brave and the celebrations began.

Murray, with tearful eyes raised to the heavens, was lost in relief and, perhaps, a little joy. As previously in the championships, he raised his fingers and mouthed what might have been a little prayer. He would not say.

Afterwards he was not allowed to forget the magnitude of his mission when, trailing away down the tunnel with the cheers still ringing in his ears, from the court and outside on the hill that once belonged to Tim Henman, Murray ran into the scheduled ambush of the BBC's Garry Richardson.

Murray sometimes looks as if he would rather be quizzed by Jeremy Paxman or Alan Partridge. Or both. Richardson did his best and Murray was his polite self. "Bit of relief, excitement," he said in the shorthand that shouts let me out of here. "Such a close match. Last two sets, both of us had chances. He had a couple of unbelievable passing shots. I managed to hang tough."

As for the ending, Murray said: "I knew when it left my racket it was good. [Jo] said he thought it was wide, then said: 'Well done.' I told him it was a great tournament, and that was it. I started well, served really well. One loose serve at the start of the third set and he came back into it. He hit some unbelievable shots and I did well to hang in there. I played a couple of good points to hold in the fourth and felt more comfortable after that.

"Tried to stay calm but it's not easy. It's difficult, lot of pressure, lot of stress but you need to focus on the next point not think on the past.

"Just got to keep it together for the final. It will be one of the biggest matches of my life. I've been in finals with Roger before, must learn from my mistakes. He's playing great tennis, as always."

And what of the pointing to the sky? Would he finally share that secret with us? "I'll keep it to myself." Quite right. We can embrace him but we do not own him.

For now he has to repulse sentiment. In Lendl, then, he has the perfect mentor, a man who sat stone-faced, ignoring the tumult that erupted around him when the packed court rose to acclaim their new hero after two hours and 48 minutes of wonderful first-strike tennis.

The gesture, part of his schtick now, was a tad self-conscious perhaps but Lendl is as eccentric as his charge.

If beating the Frenchman tested Murray's nerves and ours, the final, a record eighth here for Federer, will take us all to another level. It could be memorable. It may be disastrous. It must be hoped it will not be an anti-climax, because that would so sap the spirit of a player who deserves either to win the blessed thing after all this time or to lose with character and style. It is a fair bet he will not let himself or the rest of us down, whatever the result.